event mouseover code example

Example 1: addeventlistener hover js

let test = document.getElementById("test");

test.addEventListener("mouseover", function( event ) {
  alert("mouse over test!")
  , false);

Example 2: on mouseover in javascript

The mouseover event is fired at an Element when a pointing device 
(such as a mouse or trackpad) is used to move the cursor onto the 
element or one of its child elements.